Devices for detecting movements or physical activity have been available for some time from the field of sports. For example, watches are used, which allow the pulse to be monitored. A movement sensor in a shoe allows detection of the cadence during cycling. Comparable sensors are also available in the field of medicine, with the aid of which a movement or activity profile of the patient may be established. Such movement profiles may be helpful within the scope of a diagnosis or therapy, e.g., in the case of overweight patients or during rehabilitation measures.
It is often necessary to establish a movement profile of the patient over a long period of time, for example, over 24 hours or more, in order to be able to draw conclusions about his typical movements or activities.
To establish a movement profile, movement sensors, such as acceleration sensors, are typically attached to the body of the patient, for example, on a belt. It may be established via the sensors whether the patient stands, walks, or runs. A corresponding activity profile may be established over the day and optionally the night on the basis of these data. In order to be able to optimally detect the various activities, i.e., for example, standing or walking, cycling, swimming, or jogging, the sensor is typically fastened on various body positions, e.g., on the hip, on the foot, on the thigh, on the lower leg, on the chest, or on the arm. To be able to evaluate the various movement signals from the various body positions correctly, it is necessary to interpret the sensor signals, i.e., for example, the acceleration signals, differently depending on the particular position. For this purpose, it may be necessary to use various algorithms to analyze the signals or to employ various operating modes of the sensor or of a data processing unit. Thus, for example, in the case of triathlon watches, upon a change from running to cycling, the mode of an activity-detecting watch is manually changed over in order to be able to correctly establish the step count during running or the cadence during cycling. In the case of other applications, it is necessary to change the position of the movement sensor on the body during different activities, i.e., the sensor is initially worn on the hip and later on the lower leg, for example. A changeover of the operating mode is also necessary.
However, a changeover or a change of the operating mode is primarily problematic in the field of medicine and primarily represents an impediment in the case of older patients or patients who are restricted in any way. This may be because the particular patient is possibly not technically adept. The operation of a button or the operating selection via a menu may be difficult in the case of small buttons or a small display screen, in particular if the patient is restricted with respect to motor skills or vision. Above all, a changeover of the operating mode requires a certain attentiveness and concentration, which may not always be expected in particular in the case of longer-term establishment of a movement profile over multiple hours or over an entire day, so that deficient operation of corresponding sensors and therefore incorrect interpretation and classification of the sensor signals easily occur. Of course, such incorrectly established movement profiles are not very meaningful.